The £15m winger was replaced in the 73rd minute of his full Premier debut just two minutes after set- ting up Robin van Persie’s equaliser.

The surprise decision, which eventually led to United’s winner, sparked a furious response with visibly stunned skipper Van Persie, shouting “no, no” to the bench.

But Wenger said: “I’ve been 30 years a manager and made 50,000 substitutions and I do not have to justify every single decision I make.

“I can understand the fans are upset about the substitution, especially when it doesn’t work. It means I made the right decision (in picking Oxlade-Chamberlain) at the start of the game.

“He had started to fatigue and stretch his calf. He was sick in the week. Arshavin is captain of the Russia national team. You have an 18-year-old kid who’s playing his second or third game and a player who’s captain of his country and they are querying the substitution? Let’s be serious.

“People pay for their tickets and are free to express their emotions. That doesn’t mean they’re right always.”

Antonio Valencia scored United’s first and made a mug of Arshavin to set up Welbeck’s winner.

Wenger was seething as a third straight defeat left them in fifth, but he refused to blame Arshavin.

“It was important not to make a mistake, tactically or attention- wise, especially on the flank,” he added.

“We were caught. But if you expect me to blame an individual, it will not happen. We win and lose together.

“If I’ve made a mistake, I’m sorry. I’m like a player. I’m not completely sure.”

Ex-United skipper Gary Neville said of Arshavin: “He looks the most disinterested player in the league, to me. I think he wants to go back to Russia. Well, go. The fans don’t want him.”

Sir Alex Ferguson hailed Welbeck, saying: “Danny’s fantastic with his work-rate and movement all the time on the shoulder of the defender and being ready to run through. He could have scored five.”